I only have an electronic Brick (oops, I STILL need to go to the bookstore and pick up one) and that thing is littered with highlights marking passages I like. I always reserve the gold color for deaths.

As for my other books... I mark them up. Don't shoot!It really depends on what book I'm reading. My pretty pink Alice in Wonderland Barnes & Noble leatherbound classic book will never be touched, for instance. Probably not my "designer designed" copy of Wuthering Heights either.

But books like The Book Thief or Catcher in the Rye or Pride and Prejudice or The Perks of Being a Wallflower... I attack those with a highlighter and pen!

I use a different color for each read-through. So for the first read-through I use a pink pen and highlighter, second green, third blue, on and on. That way I know, "this is what I was thinking the first time I ever read this". Then when I mark near it a second time and read back over that a third time, I see, "this is how my thoughts changed to this certain event/quote/dialogue now that I know the full plot and what the ending is".

It's cool to see what was going through my head at that point in time!

I'm really OCD when it comes to my books so I try my best to take care of them and not break the spines or turn down corners of pages. That is why I love my nook color so much. I can highlight and underline passages I love without messing my book up.

" He makes no vain sacrifice who fights for a cause. All here are ready to die so that our brothers may live as free men. Liberty... sweet liberty... come fight with those who defend you." ----Enjolras.

I tend to really dislike writing in my books, whether they're books I'm reading for fun or whether they're school books. Sometimes I'll stick Post-Its in when I feel like annotating, but even then, the notes don't tend to stay in my books for very long. I don't have any objection to those who *do* write in their books, though, as long as the original text is still readable. (Plus, other people's notes in textbooks which I bought used have been quite helpful to me in school on a few occasions. )

I don't like writing in fiction books, for me it interrupts the flow of the story if you're constantly stopping and making notes of things or marking it. Plus, I'm not sure what insight I'd like to write in the brick, other than maybe translations from French lines (but most of those are in the back of the book or I can figure them out). My copy on Kindle Fire, though, has lots of bookmarks and highlights in it to make it easier to find certain parts I'd need to reference later, or just lines I like.

Generally I just don't write in books, other than maybe the month & year I bought it for the sake of remembering. For my summer reading non-fiction books though, I usually try to do a brief overview of the chaper on the first or last page of that chapter for the sake of easy reference (It's kind of pointless for ones like How To Read Literature Like a Professor because the chapter title gives enough away for me to remember, but probably saved my life for Guns Germs & Steel because man that book is tedious and there was no way I would read back through the chapter to find things for the stupid essays we had to do for each one).

I underline all kinds of books, fiction or otherwise. But I must, must use a sharpened pencil. I don't mind second-hand books that are marked with a highlighter but pen marking just annoys me. I know a few people who do it but I can't understand them!

In my physical copy of Hapgood I actually commented on the story and made notes in the margins with pencils. In my Signet classics copy I wrote down the page numbers of passages that I liked or wanted to be able to find again on notecards that I keep in the back of the book. I actually have annotated my online copy of Hapgood quite a bit though, mostly references that Hugo makes.